Electric-arc device



E. 1., HARRINGTON ELECTRIC ARC DEVICE Filed Maich 22, 1921 Nov. 24 1925.

PIG -2- lNVENTOR EETLE LHARR'INGTON TORNEY Patented Nov. 24, 1925.

UNITED STATES PATENT OFFICE.

ERTLE LESLIE HARRINGTON, 0F SASKATOON, SASKATCHEWAN, CANADA, ASSIGNOR '10 WESTINGHOUSE LAME COMPANY, A COREORATION OI PENNSYLVANIA.

ELECTRIC-ARC DEVICE.

Application filed March 22, 1921.

To all whom it may concern:

Be it known that I, En'rm LESLIE HAR- RINGTON, a citizen of the United States, anda resident of Saskatoon, Saskatchewan, Canada, have invented a new and useful Improvement in Eleetric-Arc Devices, of which the following is a specification.

My invention relates to devices for rectifying alternating currents and more espe cially to the type of rectifier employing enclosed arcs.

An object of this invention is the provision of a rectifier which will have a long operating life.

Another object is the provision of a rectifier which may be started at normal voltage and requires simple auxiliary apparatus for maintaining its operation.

My invention is embodied in a device containing a cathode of highly refractory material, such, for example, as tungsten, which serves when incandescent as the starting cathode, a cathode of a vaporizable material such as mercury which serves as the operating cathode, and anodes having a heat dissipating capacity suflicient to enable them to operate at a temperature below that at which electron emission is appreciable, this device being filled with an inert gas at an appreciable pressure, preferably of the order of.

magnitude of atmospheric pressure.

Prior devices which employ some of the principles of the present invention have a number of disadvantages such as the necessity for a complicated starting equipment, non-automatic starting and a cathode which is electrically disintegrated by the action of the arc during theoperation of the device.

The device embodying my invention provides means whereby an arc may be readily started between electrodes. one of which, the cathode. is adapted to be independently heated by passage of current analogous to a lighting filament, but this arrangement possesses a limitation in the fact that electrical disintegration causes the filament to wear away locally and break if the filament is used as a cathode throughout the life of the device. However, my device provides for the transfer of the are soon after starting, from the corrodible to a non-corrodible cathode. The present invention thereby provides a device having a very long life.

My invention is more fully set forth in the following description taken in connec- Serial No. 454,387.

tion with the accompanying drawings, of which Fig. 1 illustrates a device embodying my invention containing an inert gas and capable of full-wave rectification; Fig. 2

illustrates a form of my invention adapted for half-wave rectification and Fig. 3 is a diagram of sultable electrical connections for the full wave rectifier shown in Fig. 1.

Referring to the drawings and more par-.

5, which constitutes the operating cathode. The starting cathode 3 is adapted to be heated to incandeseence from any convenient source of current, for example, a battery as indicated at 19 Fig. 3.

The lower end of a conductor 6 is immersed in the mercury and constitutes a lead-in wire for both the starting cathode 3 and the operating cathode 5. i

A pair of electrodes 7 and 8 are located within the envelope 1 and serve as anodes in the operation of the device. These electrodes are conveniently supported on the lower end of the dependent conductors 9 and 10. y

The construction shown in Fig. 2 is substantially identical with the construction shown in Fig. 1 except that an anode 8 is,

omitted, thus adapting it for half wave rectification.

The envelope 1 is exhausted of gases and water vapor. Gases occluded in the materials of the device are largely eliminated by heating the latter to a temperature higher than the temperature to which they will be subjected in practical use and evacuating the evolved gases and vapors. One method of doing this is to operate the device while it is on the exhaust pump and before sealing the envelope.

- After the tube has been freedfrom deleterious gases and vapors, an inert gas, such as argon, neon or nitrogen, is admitted into the bulb at a considerablepressure. Argon gas of substantially one hundred per, cent purity is preferred and I have been accustomed to use-a pressure of nine tenths otan atmosphere, but my device is practical using a wide range of pressures.

As shown in Fig. 3. the anodes 7 8 may be connected to the. terminals of 'a source of alternating current, such as the secondary of a transformer 13, the operating cathode 5 and a terminal of the st-artin cathode "3 being connected to an intermediate point ofpotential in series with a load 14, and a se-- ries resistance. 15. In starting the device the necessary connections are made by .which the. starting cathode 3 is heated to incandescence and an are started between the electrodes 7,. 8 and cathode 3. Rectification of the alternating current takes place by reason of the fact that an arc exists between a hot body such as the incandescent cathode 3 and a coin ically, it may be that the electron emission from the filament breaks down the negative electrode reluctance around the mercury and thus makes it possible for the arc to start. The heating current of the cathode 3 is then cut off by opening circuit 17, whereby the arcs are totally transferred to the operating cathode 5. In the half wave modification as illustrated in Fig. 2, it is necessary, during the operation of the rectifier, to maintain the cathode 3 at incandes: cence electrically. The current in both forms of thedevice is carried between the "anode 7 or theanodes 7, 8 and the mercury cathode 5 partly b mercury vapor and partly by argon. lthough the current is carried largely by mercury vapor the presence of the argon as another conducting me- .dium aids in stabilizing the are at low current values.

It is to be understood that, while I have herein described and illustrated an emb odiment of my invention' illustrating specifically the principles thereof, the invention is not to be limited to the details hereinshown or described: that many modifications therein will readily suggest themselves without departing from the s irit-thereof, and that'I desire to'be limite only by the scope of the a pended claims.

What is claimed is:..

-1. An electric arc device comprising a sealed envelope containing a gas inert with respect to the operating elements of the device and of such pressure as to stabilize the are, an anode, an incandescible starting cathode, a va orizable operating cathode, a stem for sai device and an independent electrical connection for each' of sald electrodes sealed through said stem in a single press, the circuit to said incandescible cathode being completed through and dependent upon the va-porizable cathode. 2. A rectifier comprising a sealed envelope, a gaseous atmosphere within said envelope at such pressure as to stabilize the arcat low current values, said envelope also containing an anode having a heat dissipating capacity suflicient to permit it to be operable 'below the temperature at which appreciable electron emission occurs, a starting element, an operating vaporizable cathode, an electrical connection between the starting element and the vaporizable cathode and a, separate conductor for each of said electrodesextending inwardly from a common portion of the envelope.

3. A rectifier comprising a sealed envelope,

a gaseous atmosphere within said envelope at such pressure as to stabilize the are at low current values, said envelope also containing an anode having a heat dissipating capacity sufiicient to permit it to be operable below the temperature at which appreciable electron emission occurs, a conducting incandescible starting element, an operat ng vaporizable cathode. and a separate leading-in conductor-for each of said electrodes extending downwardly from a common portion of the envelope.

4. A rectifier comprising a sealed envelo c containing a gas inert with respect to t e operating elements, and at such a pressure as ,to cause stabilization of the are, an anode having a heat dissipating capacity suflicient elqw the tem to permit it to be operable WP perature at which appreciable electron emission occurs, a starting element, an operating vaporizable cathode and separate leading-in conductors for each of said electrodes sealed through a common portion of the envelope.

5. A rectifier comprising a sealed envelope containing a gas inert with respect to the operating elements and at such a pressure as to cause stabilization of the are, an anode having a heat dissipating capacity suflicicnt to permit it to be operablebelow the tem-' perature at which appreciable electron emis sion occurs, a conducting incandescible auxiliary cathode, means for heating said cathode, an operating cathode of vaporizable r material, a stem for said device and separate leading-in conductors for each of said electrodes sealed through said stem in a common ress.

6. rectifier comprising a. sealed envelope having a neck and body portion and cona stem within said neck portion and separate leading-in Wires for each of said electrodes sea-led through said stem in a common press.

7. A rectifier comprising a sealed envelope containing a filling of argon at a considerable pressure, an anode having a heat dissipating capacity sufi'icient to permit it to be operable below the temperature at which appreciable electron emission occurs, an incandescible metallic auxiliary cathode of refractory material, and an operating metallic auxiliary cathode of refractory material, and an operating metallic cathode of vaporizable material, the circuit for said in candescible cathode being completed through and dependent upon the operating cathode.

8. A rectifier comprising a sealed envelope containing a filling of argon at a considerable pressure and containing at the operating temperature of the device the vapor of mercury, an anode having a heat dissipating capacity sufficient to permit it to be operable below the temperature at which appreciable electron emission occurs, an incandescible metallic auxiliary cathode of refractory material, and an operating cathode of mercury, the auxiliary cathode dipping into the mercury cathode and having its circuit completed through and dependent upon said mercury cathode and conductors for each of said electrodes extending into the envelope from above the surface of said mercury cathode.

9. A rectifier comprising a sealed envc lope, a filling of argon therein and containing at the operating temperature of the device the vapor of mercury, said envelope also containing an anode having a heat dissipating capacity suflicient to permit it to be operable below the temperature at which appreciable electron emission occurs, a starting cathode of tungsten, and an operating cathode of mercury, said tungsten cathode contacting with the mercur cathode and having its circuit complete through and dependent upon the mercury of said cathode.

10. A rectifier comprising a sealed envelope, a stem therefor, a plurality of conducting elements extending through said stem,

an anode supported by one of said elements,

an incandescible starting cathode supported by another of said elements and a pool of vaporizable material in contact with another of said elements and with said incandescible cathode. I

11. A rectifier comprising a sealed envelope, a plurality of conductors extending through one portion thereof, a plurality of anodes secured to certain of said conductors, an incandescible cathode secured to another of said conductors and positioned between said anodes, a pool of a conducting vaporizable material within said envelope and in contact with another of said conductors and said incandescible cathode.

12. A rectifier comprising an envelope having a body portion and a single neck por tion, a stem having a press within said neck portion, a pair of anodes and a pair of cathodes in said body portion and a leading-in conductor for each of said electrodes sealed through the stem in a single press.

13. A rectifier comprising an envelope having a stem, said envelope containing a pair of anodes, an incandescible cathode, and a vaporizable cathode, a current conductor being provided for each of said electrodes sealed through said stem in a single press.

14. A mercury vapor rectifier comprising an envelope containing a pair of anodes, a mercury cathode, and an incandescible starting cathode dipping into said mercury cathode and having its circuit completed thereby and a plurality of leading-in conductors extending into said envelope from a common portion thereof and joined to each of said electrodes.

15. A mercury rectifier comprising an envelope containing a filling of argon gas, an anode and a plurality of cathodes, one of said cathodes consisting of a mercury pool and another of an incandescible element dipping into said pool and a leading-in conductor for each of said electrodes extending into the envelope from a common part thereof above said mercury 001, one of said conductors extending into t e mercury pool and another being joined to the free end of "said incandescible element.

In testimony whereof, I have hereunto subscribed my name this seventeenth day of February 1921.

ERTLE LESLIE HARRINGTON. 

